[R] Concave hull

[Remko Duursma]

Oh right.... I think I did not catch that *because of* the caps. Sorry.

r

-------------------------------------------------
Remko Duursma
Post-Doctoral Fellow

Centre for Plants and the Environment
University of Western Sydney
Hawkesbury Campus
Richmond NSW 2753

Dept of Biological Science
Macquarie University
North Ryde NSW 2109
Australia

Mobile: +61 (0)422 096908
www.remkoduursma.com



On Thu, Nov 26, 2009 at 10:51 AM, Barry Rowlingson
<b.rowlingson at lancaster.ac.uk> wrote:
> On Wed, Nov 25, 2009 at 11:39 PM, Remko Duursma <remkoduursma at gmail.com> wrote:
>> See the function 'convhulln' in the 'geometry' package. It uses this
>> algorithm : http://www.qhull.org/
>
>  That looks like a CONVEX hull, the original poster asked about
> CONCAVE hulls (and in all CAPS to emphasise this!).
>
>  I've seen various algorithms for generating 'concave hulls' of point
> sets, the one that tops google searches is not available in source
> code but there is a web applet and set of java class files which
> appear to be based on a patented algorithm.
>
>  There's a lot of discussion on algorithms for this, and some
> implementations by processing the point data with GRASS. There main
> discussion appears to be to first generate the convex hull and then
> replace single edges with two edges based on some minimum or maximum
> distance criteria...
>
>  Couldn't find an implementation in R or Python though...
>
> Barry
>